Towards a reconstruction of Marion Island’s glacial history
- Authors: Rudolph, Elizabeth
- Date: 2020
- Subjects: Glacial landforms Geomorphological mapping
- Language: English
- Type: Thesis , Doctoral , PhD (Geography)
- Identifier: http://hdl.handle.net/10353/18531 , vital:42581
- Description: Southern Hemisphere glacial chronologies can provide valuable insights into interactions between glaciation and past climate changes. The sub-Antarctic Islands provide a valuable terrestrial record of glacial chronologies for the Southern Hemisphere, since they are unique, not only in size and topography, but also in oceanic situation when compared to other continental landmasses (e.g. Antarctica or Patagonia). On sub-Antarctic Marion Island, southern Indian Ocean, the exact timing and extent of the local Last Glacial Maximum is not yet known as glacial reconstructions have mostly been based on palynological proxies and relative-age dating techniques. This study presents 29 cosmogenic 36Cl exposure ages of deglaciated bedrock surfaces and moraine deposits from Marion Island. In addition, a comprehensive glacial-geomorphological map, which in conjunction with exposure ages provide improved temporal and spatial constraints for the island’s glacial history. Results show that the ice reached a local Last Glacial Maximum before 56 ka ago and retreated, with minor stillstands, until ~17 ka. This early deglaciation left island surfaces below 850 m a.s.l. ice-free after ~19 ka, and any subsequent advances during the Late Glacial or Holocene cooling periods would have been restricted to the interior. This glacial chronology is similar to that of some other sub-Antarctic Islands (e.g. the Kerguelen archipelago, Auckland and Campbell islands, and possibly South Georgia) and a number of other Southern Hemisphere glaciers (e.g. in Patagonia and New Zealand) and adds to evidence that suggest the Southern Hemisphere was in a glacial maximum earlier than the global LGM. A combination of climatic drivers such as declining temperatures, a northward migration of oceanic fronts and the Southern Hemisphere Westerly Winds (causing precipitation changes), as well as the physiography of Marion Island, created optimal conditions for glacier growth during Marine Isotope Stage 4 (MIS 4; ~65 ka ago) instead of the global LGM in MIS 2 (~18 ka). These findings redefine the glacial history of Marion Island, and have implications for future investigations on post-glacial landscape development and ecological succession.
- Full Text:
- Authors: Rudolph, Elizabeth
- Date: 2020
- Subjects: Glacial landforms Geomorphological mapping
- Language: English
- Type: Thesis , Doctoral , PhD (Geography)
- Identifier: http://hdl.handle.net/10353/18531 , vital:42581
- Description: Southern Hemisphere glacial chronologies can provide valuable insights into interactions between glaciation and past climate changes. The sub-Antarctic Islands provide a valuable terrestrial record of glacial chronologies for the Southern Hemisphere, since they are unique, not only in size and topography, but also in oceanic situation when compared to other continental landmasses (e.g. Antarctica or Patagonia). On sub-Antarctic Marion Island, southern Indian Ocean, the exact timing and extent of the local Last Glacial Maximum is not yet known as glacial reconstructions have mostly been based on palynological proxies and relative-age dating techniques. This study presents 29 cosmogenic 36Cl exposure ages of deglaciated bedrock surfaces and moraine deposits from Marion Island. In addition, a comprehensive glacial-geomorphological map, which in conjunction with exposure ages provide improved temporal and spatial constraints for the island’s glacial history. Results show that the ice reached a local Last Glacial Maximum before 56 ka ago and retreated, with minor stillstands, until ~17 ka. This early deglaciation left island surfaces below 850 m a.s.l. ice-free after ~19 ka, and any subsequent advances during the Late Glacial or Holocene cooling periods would have been restricted to the interior. This glacial chronology is similar to that of some other sub-Antarctic Islands (e.g. the Kerguelen archipelago, Auckland and Campbell islands, and possibly South Georgia) and a number of other Southern Hemisphere glaciers (e.g. in Patagonia and New Zealand) and adds to evidence that suggest the Southern Hemisphere was in a glacial maximum earlier than the global LGM. A combination of climatic drivers such as declining temperatures, a northward migration of oceanic fronts and the Southern Hemisphere Westerly Winds (causing precipitation changes), as well as the physiography of Marion Island, created optimal conditions for glacier growth during Marine Isotope Stage 4 (MIS 4; ~65 ka ago) instead of the global LGM in MIS 2 (~18 ka). These findings redefine the glacial history of Marion Island, and have implications for future investigations on post-glacial landscape development and ecological succession.
- Full Text:
Customary marriage and family practices that discriminate against amaXhosa women: a critical study of selected isixhosa literary text
- Authors: Mbatyoti, Pheliwe Yvonne
- Date: 2019
- Subjects: Forced marriage -- South Africa -- Eastern Cape Customary law -- South Africa Xhosa (African people) -- Social life and customs
- Language: English
- Type: Thesis , Doctoral , D Litt et Phil (African Studies)
- Identifier: http://hdl.handle.net/10353/10736 , vital:35731
- Description: In many parts of Africa, the cultural practices and customs that were in use over the ages are still largely in place today. Many of these practices discriminate against individuals and compromise their human rights, particularly the rights of African women. The aim of this investigation is to study customary marital practices among the amaXhosa in order to establish their effect on modern amaXhosa society. In addition, this includes other discriminatory practices, such as the diminished status of wedded women. Within the study, the social status of women before and after 1994 is dealt with as depicted in the selected texts. The study further determines the current social status of married women under the current dispensation and finds out whether the rights of married women are sufficiently recognised in the texts under discussion. It is clear therefore that whilst Africa has made good progress on the political front, the same cannot be said for some of the cultural values that are still adhered to in the present age. This applies in particular to the rights of women in an African society. Globally, women and girls suffer the harmful and life-threatening effects of discriminatory traditional and cultural practices that continue under the guise of social, cultural and religious ceremonies. In the democratic South Africa, there is growing concern and awareness that some cultural practices are harmful to women and girls. The study analyses a number of texts namely, novels and drama, that were published before and after the 1994 era in South Africa with aims and objectives being outlined in Chapter 1. Chapter 2 is devoted to the theoretical framework, which includes the general theory pertaining to the status of women, feminism and human rights. Secondly, it deals with African theory pertaining to the status of African women as well as their rights; finally, it reflects on the role of women in societies where traditional marriage custom is still in use. Chapter 3 analyses the depiction of customary marriage as a theme in isiXhosa prose before and after 1994. Chapter 4 examines the depiction of customary marriage in v isiXhosa drama before and after 1994 and focuses more on human rights elements. Chapter 5 summarises the arguments distilled from the analysed works. The researcher came to the conclusion that the practice of forced marriage does not occur in amaXhosa society only but it is also found on a wider scale on the rest of the African continent and beyond. The study was concluded with a set of recommendations that were made to combat the scourge of anti-feminism that is found in modern society.
- Full Text:
- Authors: Mbatyoti, Pheliwe Yvonne
- Date: 2019
- Subjects: Forced marriage -- South Africa -- Eastern Cape Customary law -- South Africa Xhosa (African people) -- Social life and customs
- Language: English
- Type: Thesis , Doctoral , D Litt et Phil (African Studies)
- Identifier: http://hdl.handle.net/10353/10736 , vital:35731
- Description: In many parts of Africa, the cultural practices and customs that were in use over the ages are still largely in place today. Many of these practices discriminate against individuals and compromise their human rights, particularly the rights of African women. The aim of this investigation is to study customary marital practices among the amaXhosa in order to establish their effect on modern amaXhosa society. In addition, this includes other discriminatory practices, such as the diminished status of wedded women. Within the study, the social status of women before and after 1994 is dealt with as depicted in the selected texts. The study further determines the current social status of married women under the current dispensation and finds out whether the rights of married women are sufficiently recognised in the texts under discussion. It is clear therefore that whilst Africa has made good progress on the political front, the same cannot be said for some of the cultural values that are still adhered to in the present age. This applies in particular to the rights of women in an African society. Globally, women and girls suffer the harmful and life-threatening effects of discriminatory traditional and cultural practices that continue under the guise of social, cultural and religious ceremonies. In the democratic South Africa, there is growing concern and awareness that some cultural practices are harmful to women and girls. The study analyses a number of texts namely, novels and drama, that were published before and after the 1994 era in South Africa with aims and objectives being outlined in Chapter 1. Chapter 2 is devoted to the theoretical framework, which includes the general theory pertaining to the status of women, feminism and human rights. Secondly, it deals with African theory pertaining to the status of African women as well as their rights; finally, it reflects on the role of women in societies where traditional marriage custom is still in use. Chapter 3 analyses the depiction of customary marriage as a theme in isiXhosa prose before and after 1994. Chapter 4 examines the depiction of customary marriage in v isiXhosa drama before and after 1994 and focuses more on human rights elements. Chapter 5 summarises the arguments distilled from the analysed works. The researcher came to the conclusion that the practice of forced marriage does not occur in amaXhosa society only but it is also found on a wider scale on the rest of the African continent and beyond. The study was concluded with a set of recommendations that were made to combat the scourge of anti-feminism that is found in modern society.
- Full Text:
- «
- ‹
- 1
- ›
- »